The technical and scientific information is presently available which, if properly utilized, could facilitate the early diagnosis of breast cancer. Hopefully, it could likewise reduce the high mortality rate of breast cancer. Due to the lack of adequately trained professional and allied health personnel, a massive screening program on a national scale is unwarranted and would be unproductive at this time. Based upon our experience in the U.C.L.A. Center for Health Sciences, the establishment of screening clinics for women 40 years of age and over in conjunction with a cervical cancer detection clinic in a number of large medical centers is indicated. Thermography as a prescreening modality should be investigated further.

An interpenetrating polymer network, IPN, is defined as a combination of two polymers in network form, at least one of which is synthesized and/or cross-linked inthe immediate presence of the other. In this chapter, the literature and patents on IPNs are reviewed from 1979 to the present. Many compositions contain two continuous phases, which contribute to their toughness. A new area of IPN interest is the thermoplastic IPN concept, where the IPNs have physical rather than chemical cross-links..A.N INTERPENETRATING POLYMER NETWORK, IPN, previously was defined as a combination of two polymers in network form, at least one of which is synthesized and/or cross-linked in the immediate presence of the other (I). Although this definition still fits most materials called IPNs, now some hybrid compositions, such as the thermoplastic IPNs, call for a broader view. This chapter will review the IPN literature from 1979 to the present. The choice of year 1979 is dictated by the advent of several reviews covering the literature up to that time (1-4). During the 1960s and 1970s, several synthetic methods were developed to prepare IPNs. These methods include materials now called sequential IPNs, where the networks are made sequentially, and simultaneous interpenetrating networks, SINs, where both monomers are mixed together and polymerized by independent and noninterfering routes. Surprisingly, most workers find it is better to polymerize one of the two networks in an SIN faster than the other, as will be explored further. Other methods of synthesis include latex IPNs, where both networks are on each latex particle, and interpenetrating elastomeric networks, IENs, where two latexes are mixed and subsequently cross-linked.

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